Age of onset in bipolar and unipolar illness with and without delusions or hallucinations

This study examined the differential association of unipolar and bipolar major affective disorder and the presence or absence of delusions or hallucinations with a number of age of onset indices. Earlier age of onset tended to be found in bipolar patients and patients with psychotic features. When the joint effect of polarity and psychotic features were examined, polarity was more highly related to various age of onset indices than psychotic features. However, these features were uniquely associated with a subset of indices beyond that accounted for by bipolarity. The implications of these findings are discussed.